Put drained beans in a bowl.,Slice water chestnuts over beans. Saute onions and mushrooms together in margarine.,Pour over top of beans.,Mix soup, soy sauce and half of the mushroom liquid together.,______,Bake, covered, for 40 minutes at 350°.,Remove from oven and cover with French fried onions. Bake, uncovered, for 8 to 10 minutes.